package org.shiwen.week2.thursday;

import java.util.Scanner;

public class q2_2 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入圆的半径");
        double pi = 3.14;
        double r = sc.nextDouble();
        double area = pi * r * r;
        System.out.println("半径为"+r+"的圆的面积是：" + area);
    }
}
